Rainbow Electronics MAX776 - Manual (Page 8)

MAX774/MAX775/MAX776
-5V/-12V/-15V or Adjustable,
High-Efficiency, Low I
Q
Inverting DC-DC Controllers
8 _______________________________________________________________________________________
______________________________________________________________Pin Description
PIN NAME FUNCTION
1 OUT
2 FB
3 SHDN
4 REF 1.5V reference output that can source 100 µ A. Bypass to ground with 0.1 µ F.
5 V+ Positive power-supply input
6 CS Noninverting input to the current-sense comparator. Typical trip level is 210mV (relative to V+).
7 EXT The gate-drive output for an external P-channel power MOSFET. EXT swings from OUT to V+.
8 GND Ground
The sense input for fixed-output operation (V FB = V REF ). OUT is connected to the internal voltage divider,
and it is the negative supply input for the EXT driver.
Feedback input. When V FB = V REF , the output will be the factory preset value. For adjustable operation,
use an external voltage divider, as described in the Adjustable Output section.
Active-high shutdown input. With SHDN high, the part is in shutdown mode and the supply current is less
than 5
µ A. Connect to GND for normal operation.
____________________________Typical Operating Characteristics (continued)
(T A = +25°C, unless otherwise noted.)
CIRCUIT OF FIGURE 2
V+ = 6V, V
OUT = -5V
A: I LOAD , 30mA TO 1A, 1A/div
B: V OUT , 100mV/div, AC-COUPLED
LOAD-TRANSIENT RESPONSE
100 µ s/div
A
B
CIRCUIT OF FIGURE 2
V
OUT = -5V, I LOAD = 1A
A: V+, 3V TO 8V, 5V/div
B: V
OUT , 100mV/div, AC-COUPLED
LINE-TRANSIENT RESPONSE
2ms/div
A
B